Environmental Engineering Reference
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are non-native could undermine the very biological entities that may be the most likely to succeed in a
rapidly changing world.”
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Ecosystems, says Chris Thomas, “don't have a preordained cast list. They dissolve and create en-
tirely new communities,” like turning the mirrors in a kaleidoscope. Novelty is the norm in nature. It
always has been. Ecologists touring the world thousands of years ago would have seen most of the same
species we see today. But they would have been arranged differently. At the end of the last ice age—the
last time we had big climate change—tree species migrated north as the ice retreated. They were re-
claiming old territory, but they didn't go back at the same speed or to the same places. As a result, new
combinations of species emerged. New ecosystems. In New England, beech and hemlock trees are today
regarded as long-standing ecosystem companions. Yet pollen studies show that as the ice retreated, hem-
lock appeared in Massachusetts nine thousand years ago, while it was another two thousand years before
beech showed up.
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This reconstruction was made by ecologists in the 1980s. Thomas says that it was one of the pieces
of research that first opened the eyes of his generation to the idea that the Clementsian orthodoxy might
be wrong. “Back then,” he tells me, “ideas about ecological communities and coevolution were domin-
ant. So when ecologists started reporting this stuff, I remember thinking: wow. It contradicted everything
I had been taught. It started a much more individualistic view of things. We realized that botanical com-
munities don't move en masse. Individual organisms move. In the end, it is they that are the biological
building blocks, not ecosystems.”
Another young researcher who took that message was Stephen Jackson of the University of Wyom-
ing. Few things in nature stay stable for long, he concluded. “Change, including rapid and disruptive
change, is natural,” he says. The world “has been in continual environmental and ecological flux
throughout its history. Ecological novelty is widely perceived as a threat to conservation. However, it
also comprises a reality and, more importantly, an opportunity.”
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It is also a necessity. The old wild will
have to be constantly micro-engineered to keep it functioning in an increasingly unfamiliar world. The
rest of nature—an increasingly large proportion of it—will be living in novel ecosystems, where alien
species live cheek-by-jowl with natives, all fitting in as best they can. They will have their mishaps and
disasters, their grand advances and ignominious retreats. But they will exhibit the abiding traits of real
nature—transience, dynamism, and contingency, rather than stability, permanence, and predictability.
Here we face a central paradox of conservation in the twenty-first century and beyond. Traditional
wild lands—the old-growth forests and other historic habitats—will in future be the places most depend-
ent on human intervention for their survival. In a world of climate change, where the old wild is hemmed
in by human activity, these ecosystem islands will increasingly resemble museum pieces, time capsules,
and experimental labs for scientists. They will not be wild in any true sense. On the other hand, the nov-
el ecosystems, the make-do-and-mend places, will be the ones able to stand on their own two feet. They
will be the new wild.
Nobody wants species to go extinct. Perhaps the pace of loss can be slowed. I hope so. But it is hap-
pening. What should increasingly matter for conservationists is finding ways to help nature regenerate.
That should mean supporting the new, rather than always spending time and money in a doomed at-
tempt to preserve the old. Embracing the new—striving to find what works in the new world—will often
mean making peace with old enemies, because successful alien invaders are increasingly what works in
nature. They are the winners and likely saviors. They are the ones able to reclaim the abandoned fields,
to rise up through the cracks of urban concrete jungles, to kick-start the revival of degraded forests and
shrug off the rigors of climate change. As the late Stephen M. Meyer put it, conventional notions of wild
lands “are just fantasies now. There is virtually no place left on Earth that fits this definition.”
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